JPS61211103A - Caster device - Google Patents

Abstract

PURPOSE:To enable change in direction to be easily effected in a device for traveling trucks and the like as referred to the titled by combining two rotary shafts with one shaft one another and providing semi-spheres on both sides of one of rotary shafts. CONSTITUTION:Support legs 15 are vertically arranged under the lower surface of a traveling truck, No.1 rotary shaft 17 is installed vertically but rotatably at the lower section of each of support legs 15. And a york bracket 19 in an inverted U shape is installed underneath No.1 rotary shaft 17. And a horizontal No.2 shaft 21 is installed to the york bracket so as to be perpendicular to No.1 rotary shaft 17. In addition, a through hole 23 is made at the center of No.2 rotary shaft 21 in the longer direction so as to be perpendicular to the longer direction of the shaft 21 allowing the hole to support No.3 rotary shaft 25 rotatably. Then, semi-spheres 27A and 27B are installed on both sides of No.3 shaft 25 allowing them to form a complete sphere. This configuration allows the sphere to be combined rotatably around both No.2 rotary shaft 21 and No.3 rotary shaft 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a caster device such as a movable trolley, and more particularly to a caster device having a spherical appearance.

[Technical Background of the Invention and Problems Therewith] A caster device such as a movable trolley is provided with a first rotary shaft rotatably supported perpendicularly to the movable trolley, and a caster device that is unevenly distributed from the center of the rotation axis of the first rotary shaft. Generally, a horizontal second shaft is provided at the position, and a roller is rotatably supported on this second shaft. In such a configuration, when the moving direction of the movable cart and the second axis are perpendicular to each other, the rollers rotate smoothly. In the above-mentioned state, when the movable trolley is directed to move in a direction perpendicular to the previous moving direction (direction parallel to the second axis) after stopping the movement of the movable trolley, the rollers come into contact with each other. The movable trolley moves eccentrically around the grounding point, with the radius being the dimension between the point and the rotation axis of the first rotating shaft, and the second axis becomes perpendicular to the moving direction of the movable trolley again.

That is, in the conventional Leg II device using rollers, when changing the direction of movement of the movable dolly, a large eccentric movement occurs in the movable dolly, making it difficult to stabilize the directionality of the movable dolly. Therefore, for example, in the case of a self-propelled mobile trolley, accurate control in the commanded direction from the control device is quite difficult due to the eccentric movement.

[Object of the Invention] This invention was created in view of the conventional problems as described above, and its purpose is to control the eccentric motion given to the movable dolly when changing the moving direction of the movable dolly, and to improve the movement of the movable dolly. The object of the present invention is to provide a novel caster device that maintains directionality and can easily change direction.

[Summary of the Invention] In order to achieve the above-mentioned objects, in this invention, a first rotating shaft attached to a movable trolley is provided rotatably about a vertical axis, and the first rotating shaft is unevenly located from the center of the rotating shaft. A second rotating shaft rotatably supported by the first rotating shaft is provided perpendicular to the rotational axis of the first rotating shaft at a position where the second rotating shaft is rotatably supported by the first rotating shaft, The second rotary shaft is provided with a hemispherical body that supports a third shaft extending in the direction of rotation, and is rotatable about the axis of the third shaft, and is disposed on both sides of the second rotation shaft.

[Embodiments of the Invention] Referring to FIGS. 1 and 2, a rotary plate 5 is horizontally rotatably supported at the center of the lower surface of the movable trolley 1 via a bearing 3. A rotary plate 5 is located close to
A rotation regulating device 7 that can freely regulate zero rotation is installed.

The rotation restricting device W7 is composed of, for example, a suitable clamping device that can freely clamp the peripheral edge of the rotary plate 5, and has the function of allowing rotation of the rotary plate 5 or restraining the rotation of the rotary plate 5. It is something that does.

Drive motors 9A, 9, which can freely rotate in forward and reverse directions, such as pulse motors or servo motors, are installed at symmetrical positions of the rotary plate 5.
A running wheel 13A, 13B is attached to each drive shaft 11A, 11B, which is rotated in forward and reverse directions by each drive motor 9A, 9B.

As can be understood from the above configuration, in a state where the rotary plate 5 is integrally fixed to the movable trolley 1 by the rotation regulating device 7, each drive motor 9A, 9B is appropriately controlled to control the running wheels 13A, 13B. By rotating in the same direction in the same direction, the movable trolley 1 moves linearly. Also, running wheel 1
By applying a rotation difference to 3A and 13B, the movable trolley 1 turns to the right or to the left and changes direction. Further, when the traveling wheels 13A and 13B are caused to rotate in the same direction in opposite directions, the movable cart 1 rotates about the center of the rotary plate 5.

Note that when the fixation of the rotary plate 5 by the rotation regulating device 7 is released,
In a state where the rotary plate 5 is rotatable with respect to the movable trolley 1, the above-mentioned drive motor 9A.

When the running wheels 13A and 13B are appropriately controlled by appropriately controlling the wheel 9B, the rotary plate 5 is appropriately rotated with respect to the movable trolley 1. In this case, since the frictional resistance between the rotary plate 5 and the moving carriage 1 is not strictly zero, the moving carriage 1 tends to rotate following the rotation of the rotating plate 5.
Legs II, which will be explained later! The movable trolley 1 will not rotate significantly due to the ground resistance of the device.

In order to support the movable dolly 1 in a stable posture, a plurality of locations (four locations in this embodiment) on the lower surface of the movable dolly 1 are provided.
Support legs 15 are vertically disposed on the support legs 15, and a first rotating shaft 17 is rotatably vertically disposed below each support leg 15 via a bearing. An inverted U-shaped yoke bracket 19 is integrally attached to the lower part of each first rotation shaft 17, and a horizontal second rotation shaft 21 perpendicular to the first rotation shaft 17 is attached to the yoke bracket 19. is rotatably supported via a bearing. The second rotating shaft 21 is unevenly distributed at a position appropriately spaced from the axis 17A of the first rotating shaft 17.

A through hole 23 in a direction perpendicular to the longitudinal direction of the second rotating shaft 21 is bored in the central portion of the second rotating shaft 21 in the longitudinal direction. A third shaft 25 is rotatably supported in this through hole 23 via a bearing, and hemispheres 27A and 27B are integrally attached to both ends of the third shaft 25. That is, the hemispheres 27A and 27B are provided rotatably about the axis of a third shaft provided orthogonally to the second rotation shaft 21. More specifically, by arranging the hemispheres 27A and 27B facing each other, the overall structure becomes a spherical body 29, and these two spherical bodies are rotatable around the second rotation axis 21, and are rotatable around the third axis 25. It is rotatable around the center.

In the above configuration, the intersection point P between the surface of the spherical body 29 and a straight line perpendicular to the axial center of the second rotating shaft 21 and the axial center of the third shaft 25 and the axial center of the third shaft 25 and the spherical body 29 When the intersections Q and R with the surface of the spherical body 29 are in contact with the ground, it is difficult to rotate the spherical body 29 about the third axis 25. However, the spherical body 29 and the running surface of the movable trolley 1 are theoretically in point contact, and the frictional resistance is much smaller than in the conventional roller configuration. Therefore, the slight movement of the movable trolley 1 is smooth, and this slight movement causes the intersection point P
, Q1R move away from the running surface even slightly, the spherical body 29 becomes rotatable about the third axis 25. Therefore, the rotation of the spherical body 29 in the moving direction of the movable trolley 1 is easy, and the ability to follow the movable trolley 1 is improved. That is, for example, after moving the movable trolley 1 linearly, next, the movable trolley 1 is moved in a direction perpendicular to the previous moving direction.
When moving, the two spherical bodies immediately rotate in the same direction following the movement of the movable carriage 1, so the movable carriage 1 does not make a large eccentric movement about the grounding point of the spherical body 29. Therefore, while maintaining the directionality of the mobile cart 1,
The direction of movement of the movable trolley 1 can be easily changed.

[Effects of the Invention] As can be understood from the above description of the embodiments, the gist of the invention is as stated in the claims. The moving direction of the movable cart can be easily changed, and the directionality of the movable cart can be stably maintained.

Note that the present invention is not limited to the above-described embodiments, but can be implemented in other embodiments by making appropriate changes.

[Brief explanation of the drawing]

Fig. 1 is a front view of a mobile cart embodying the present invention, Fig. 2 is an open bottom view, Fig. 3 is an enlarged sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 is an IV of Fig. 3. -TV sectional view, and FIG. 5 is a perspective view schematically showing the main parts. 1... Moving trolley 17... First rotating shaft 21...
・Second rotation axis 25...Third axis 27A127B...
・Hemisphere Figure 1 Figure 2

Claims (1)

[Claims] A first rotating shaft mounted on the movable cart is rotatably centered around a vertical axis, and a second rotating shaft is rotatably supported by the first rotating shaft at a position unevenly distributed from the center of the rotating shaft of the first rotating shaft, A third shaft is provided perpendicularly to the rotation axis of the first rotation shaft, and a third shaft is supported and provided on the second rotation shaft in a direction perpendicular to the axis of the second rotation shaft. A caster device comprising: a hemisphere rotatable around the second rotating shaft;